21-22 the best tutorial on exhaust scrubbers for marine diesel engines

Exhaust scrubbers for marine engines

Exhaust scrubbers are important for marine engines because they help to reduce the emissions from the engine. However, most people don’t know about these scrubbers and how they work. In today’s world, it is more important than ever to have efficient and reliable exhaust scrubbers for your marine engines. This is especially true when it comes to when running a marine engine in the open water. There are a lot of factors to consider when it comes to choosing the right exhaust scrubber for your engine, and we are here to help. In this post, we will cover the different types of exhaust scrubbers and give you an idea on how to choose the right one for you.

For the reduction of pollutants and contaminants, scrubbers are the best equipment in modern times. For all other means of pollutants and contaminants, removal is expensive than scrubbers. 

exhaust scrubbers for marine engines

What is a scrubber?

exhaust scrubbers for marine engines

A process or system for removing pollutants from the Engine exhaust system is known as the scrubber. This process uses liquid spray to eliminate solid and liquid pollutants and absorb or neutralizes the gaseous pollutants.

Scrubbers are helpful for the removal of pollutants and contaminants. Flue gases produce them. The scrubbers will prevent heavy damage to the environment and the human beings in the vicinity. Scrubbers can treat Sulphur dioxide, Chlorine, Hydrogen sulfide, and hydrogen chloride.

Types of scrubbers

exhaust scrubbers for marine engines
Exhaust gas scrubber

Wet scrubbing process

This system of removing the particulates from the exhaust gases is one of the oldest systems. This system uses the wet substance to remove the acidic gases. In this system, flue gases pass through a funnel, and a wet substance is sprayed on the gases. Dust and particulates are removed from the exhaust gases by use of water. A wet type of scrubber is advantageous as the system prevents a considerable range of pollutants from mixing in the air through the flue gases. A wet type of scrubbing system also removes the sulfur from the gases and prevents acid rains.

Advantages of wet scrubber

  • Effective prevention of pollutants entry in tot eh air through exhaust gases
  • Occupies less space
  • Removal of corrosive gases 
  • Reduction of fine particulates from the flue gases
  • Collection of harmful gases with particulates
  • Easy and proper handling of high humid and high-temperature gases flow.
  • Wet scrubbers only can handle the gas flow with highly explosive and flammable materials.
  • The wet scrubber has no issues in handling the dry dust combustible dry dust.
  • Installation cost is comparatively low.

Disadvantages of wet scrubbers

  • Not economical due to high maintenance cost.
  • The problem is the disposal of wet collected products with Water.
  • Contained substances need to be kept warm.
  • Dispersal of exhaust gas will reduce with the low-temperature exhaust gas.
  • Maintenance problems due to the accumulation of solids around the wet-dry interface.
  • The system will be heavy due to the collection of collected Water.

Dry scrubbing process

Dry scrubber
Image credit:- https://www.sciencedirect.com/

Dry-type scrubber has a dry absorber chamber, a regent feeding tank, a bag filter, a system for the regent feeding, and a system for the discharge of fly ash. Lime is the regent. 

The advantage of using the dry scrubbing system

  • Sludge is always dry
  • Highly efficient in the collection of acidic gases
  • Requires less space 
  • Can include a fabric fiber filter can be included in the system
  • Efficient in handling the high-temperature gas flow.
  • Low maintenance due to the simple system design with dry process.

Disadvantages of using the dry scrubbing system

  • Acid gas control efficiency is low as compared to the wet scrubber
  • Additional requirement for the disposal of unburned residual waste powder
  • Expensive scrubbing process with a dry scrubber
  • Unable to remove all kinds of contaminants from the flue gases.


In 2016 during the 70th session of MEPC (Marine Environment Committee), IMO (International Maritime Organization) had decided on a regulation w.e.f. 1st January 2020, the marine sector emission in International Water is slashed down from 3.5%m/m to 0.5%m/m. even for out-of-emission control areas such as the North American Coast.

Fuel oil sulfur level will fall from 3.5% to near 0.5%. This production will see the most considerable reduction in the transportation of fuel at any time.

Ships use the lowest fuel known as Heavy Fuel Oil with other refined oils like Marine Gas Oil, Marine Diesel Oil, Marine Fuel Oil, Light Diesel Oil, and IFO Intermediate Fuel Oil.

All the above fuels are with high sulfur contents up to to3.5% m/m. This fuel is burnt in Engines and Boilers, producing exhausts with high Sulfur oxide contents (SOx). This SOx reacts with water, Oxygen and forms Sulphuric Acids and many other secondary inorganic aerosols.

Harmful effects of Acid Rains

acid rain 412 epd acid rain

In 2005 IMO sulfur limit was 4.5% m/m and the second limit came in 2012with, a cap of 3.5% m/m. The decision to bring it down to 0.5% in 2020 was taken in 2008 and was ratified in 2016.

Due to the stringent regulation implementation, ship owners started rushing for methods to reduce the sulfur contents to 0.5% m/m by installing scrubbers and other available means to escape from heavy penalties.

Methods to reduce emissions and acid rains.

  • Use of Scrubbers (Exhaust gas cleaning system).
  • Use the Low sulphur fuel.
  • Use of LNG, LPG, Methanol, Biodiesel, Hydrogen, etc
  • Fuel cell, Wind Turbine Energy assisted propulsion

Impacts on shipping companies

  • Huge Cost in Retrofitting exhausts cleaning system, which can go up to 5 to 15 million $ per ship.
  • Maintenance of Exhaust cleaning system
  • The use of Cleaners Fuels is having a high impact on higher fuel costs. 
  • Usage of LNG is going to have a high impact on cost. The use of LNG needs the Modification of Engines and Boilers. 
  •  Engineers and operational staff need the onboard training ships for Exhaust scrubbers etc.

Required preparation

  • Cleaning of tanks for LSFO fuels
  • Arrangements for the storage of LNG by installing the tanks.
  • Arrangements to bunker for LNG and similar energies.
  • Modifications of fuel oil pipelines to avoid contaminations.
  • Acquiring of compatible grade of Lube and cylinder oil
  • Improvements in Engine and Boilers to burn LNG
  • Preparation of compliance documents.

However, to have a cleaner ocean and atmosphere, there will be a high cost that is having a direct impact on end customers. All the above actions and modifications have a better effect on the Scrubber Industries Future 2021.

New Technologies for Emission Control in Marine Diesel Engines

Emission control

New Technologies for Emission Control in Marine Diesel Engines provides a unique overview on marine diesel engines and aftertreatment technologies that is based on the authors’ extensive experience in research and development of emission control systems, especially plasma aftertreatment systems. The book covers new and updated technologies, such as combustion improvement and after treatment, SCR, the NOx reduction method, Ox scrubber, DPF, Electrostatic precipitator, Plasma PM decomposition, Plasma NOx reduction, and the Exhaust gas recirculation method. This comprehensive resource is ideal for marine engineers, engine manufacturers and consultants dealing with the development and implementation of aftertreatment systems in marine engines.

  • Includes recent advances and future trends of marine engines
  • Discusses new and innovative emission technologies for marine diesel engines and their regulations
  • Covers aftertreatment technologies that are not widely applied, such as catalysts, SCR, DPF and plasmas

Pounder’s Marine Diesel Engines and Gas Turbines

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Since its first appearance in 1950, Pounder’s Marine Diesel Engines has served seagoing engineers, students of the Certificates of Competency examinations and the marine engineering industry throughout the world.

Each new edition has noted the changes in engine design and the influence of new technology and economic needs on the marine diesel engine.
Now in its ninth edition, Pounder’s retains the directness of approach and attention to essential detail that characterized its predecessors. There are new chapters on monitoring control and HiMSEN engines as well as information on developments in electronic-controlled fuel injection. It is fully updated to cover new legislation including that on emissions and provides details on enhancing overall efficiency and cutting CO2 emissions.
After experience as a seagoing engineer with the British India Steam Navigation Company, Doug Woodyard held editorial positions with the Institution of Mechanical Engineers and the Institute of Marine Engineers.

He subsequently edited The Motor Ship journal for eight years before becoming a freelance editor specializing in shipping, shipbuilding and marine engineering. He is currently technical editor of Marine Propulsion and Auxiliary Machinery, a contributing editor to Speed at Sea, Shipping World and Shipbuilder and a technical press consultant to Rolls-Royce Commercial Marine.

* Helps engineers to understand the latest changes to marine diesel engineers
* Careful organisation of the new edition enables readers to access the information they require
* Brand new chapters focus on monitoring control systems and HiMSEN engines.
* Over 270 high quality, clearly labelled illustrations and figures to aid understanding and help engineers quickly identify what they need to know.

Lamb’s Questions and Answers on the Marine Diesel Engine

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The book is comprehensive and includes almost all topics needed to understand marine diesel engines. The book explains the role of heat in engineering science, the principles behind internal combustion engines, the role of fuels and lubricants, the cooling systems, the lubricating systems and the heat exchangers.

The book also explains the various parts of the marine engines and their functions. Air-storage tanks and air compressors are also dealt with in the book. Information on balancing and vibration, various instrumentation and control methods, along with the safety measures are covered in the book.

Lamb’s Questions and Answers on the Marine Diesel Engine was published by Butterworth-Heinemann in 1990. The eighth revised edition is available in hardcover.

A Pocket Book of Marine Engineering: Questions and Answers

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A Pocket Book of Marine Engineering: Questions and Answers is a book that covers the topic of air filter for engine in great detail. This book is a great resource for anyone who wants to learn more about this topic. The author, John Myatt, is a world-renowned expert on marine engineering. In this book, he covers everything from the basics of how these engines work to more advanced topics like choosing the right air filter for your engine. If you’re looking for a comprehensive guide to air filter for engine, this is the book for you.

This handy pocket-sized guide is filled with hundreds of questions and answers on marine engineering, covering all the basics from engines and propulsion to steering and safety. It’s perfect for anyone who wants to learn more about this fascinating subject, whether they’re studying for a qualification or just interested in how boats work. With clear explanations and plenty of diagrams, this book is an essential reference for anyone with an interest in maritime engineering.

Introduction to Marine Engineering

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This second edition deals comprehensively with all aspects of a ship’s machinery from propulsion and steering to deck machinery and electrical equipment with a strong emphasis upon correct and safe procedures.

Material has been added and revised to reflect the greater weight now being placed upon the cost-effective operation of ships; in terms of greater equipment reliability, more fuel-efficient engines, the ever-increasing shift towards automatically operated machinery, and the need for fewer engineering crew. This is an invaluable guide for professionals but equally covers the requirements for Class 4 and Class 3 Engineer’s Certificates of Competency, the first two years of the Engineer Cadet Training Scheme, and the Engineering Knowledge syllabus for the Master’s Certificate.

Diesel Generator Handbook

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Diesel Generator Handbook meets the need for an authoritative reference work covering the range of mechanical and electrical topics embodied in the practical design and application of diesel generating plant. It will be particularly welcomed in many parts of the developing world where the diesel generator is basic to the electricity supply system.

The discussion covers, in fifteen chapters, the prime mover, power ratings, synchronous generators, load assessment, control principles and systems, switchgear and controlgear, standby power, fuels and lubricating oilss, installation and commissioning, noise reduction, and plant operation and maintenance.

The book thus caters for all who are concerned with the selection, specification, testing, commissioning, operation and maintenance of diesel-based generator systems: not only the practising plant or services engineers, but also non-specialist engineers and users. The young technician or trainee engineer who is embarking on a career in the supply industry will find this handbook an invaluable investment.

L L J Mahon, FIEE, FBIM, after an engineering apprenticeship with BTH in Rugby, gained over 30 years’ experience in the design, development, manufacture, installation and commissioning of both stationary and highly specialised mobile diesel generator plant for a range of applications.

General Engineering Knowledge for Marine Engineers

General Engineering Knowledge

This textbook is key for all marine engineering officer cadets. Accessibly written and clearly illustrated, General Engineering Knowledge for Marine Engineers takes into account the varying needs of students studying “general” marine engineering, recognizing recent changes to the Merchant Navy syllabus and current pathways to a sea-going engineering career. It includes the latest equipment, practices and trends in marine engineering, as well as incorporating the 2010 Manila Amendments, particularly relating to management.

It is an essential buy for any marine engineering student. This new edition reflects all developments within the discipline and includes updates and additions on, among other things:· Corrosion, water treatments and tests· Refrigeration and air conditioning· Fuels, such as LNG and LPG· Insulation· Low sulphur fuels· Fire and safety Plus updates to many of the technical engineering drawings.

Marine Auxiliary Machinery

Marine Auxiliary Machinery

“The strength and depth of information contained in the book, together with the clarity of the line drawings, makes it ideal for marine engineers studying for certificates of competency but it would also be extremely useful for marine engineer cadets and undergraduate marine engineers. Practising marine engineers, both ashore and afloat would also benefit from possession of this volume which is highly recommended.” Marine Engineer’s Review

Marine Electrical Equipment and Practice

Marine Electrical

This book Caters to marine engineer candidates for Department of Transport Certification as Marine Engineer Class One and Class Two. It covers the various items of ships’ electrical equipment and explains operating principles.
David McGeorge is a former lecturer in Marine Engineering at the College of Maritime Studies, Warsash, Southampton. He is the author of General Engineering Knowledge.

Practical Marine Electrical Knowledge

Practical Marine Electrical Knowledge

This book’s objective is to help marine and electrical engineers acquire the knowledge required by STCW for management and operational level endorsements and to become more familiar with various electrical applications that can be found on board ship

Blog Conclusion

We hope that you enjoyed our blog post on exhaust scrubbers for marine engines. The main goal of this blog post is to introduce the students to the concept and give them ideas for how this type of technology can benefit marine engines. We created this blog post to help to boost the search rankings for exhaust scrubbers for marine engines. If you have any comments or questions please don’t hesitate to get in touch with us. Thank you, we hope to hear from you soon.

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